package com.xuyiwei.mayi;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

/**
 * Created by xuyiwei on 2019/4/15.
 */
class ServerHandler extends ChannelHandlerAdapter {

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
        System.out.println("exceptionCaught");
    }

    @Override
    public void disconnect(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
        super.disconnect(ctx, promise);
        System.out.println("disconnect");

    }

    @Override
    public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
        super.close(ctx, promise);
        System.out.println("disconnect");

    }

    /**
     * 当通道被调用,执行该方法
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        // 接收数据
        String value = (String) msg;
        System.out.println("Server msg:" + value);
        // 回复给客户端 “您好!”
        String res = "好的...";
        ctx.writeAndFlush(Unpooled.copiedBuffer(res.getBytes()));
    }

}

public class NettyServer {

    public static void main(String[] args) throws InterruptedException {
        System.out.println("服务器端已经启动....");
        // 1.创建2个线程,一个负责接收客户端连接， 一个负责进行 传输数据
        NioEventLoopGroup pGroup = new NioEventLoopGroup();
        NioEventLoopGroup cGroup = new NioEventLoopGroup();
        // 2. 创建服务器辅助类
        ServerBootstrap b = new ServerBootstrap();
        b.group(pGroup, cGroup).channel(NioServerSocketChannel.class).option(ChannelOption.SO_BACKLOG, 1024)
                // 3.设置缓冲区与发送区大小
                .option(ChannelOption.SO_SNDBUF, 32 * 1024).option(ChannelOption.SO_RCVBUF, 32 * 1024)
                .childHandler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel sc) throws Exception {
//                        ByteBuf buf = Unpooled.copiedBuffer("_mayi".getBytes());
//                        sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, buf));
                        sc.pipeline().addLast(new StringDecoder());
                        sc.pipeline().addLast(new ServerHandler());
                    }
                });
        ChannelFuture cf = b.bind(8080).sync();
        cf.channel().closeFuture().sync();
        pGroup.shutdownGracefully();
        cGroup.shutdownGracefully();

    }

}

